New sesquiterpene coumarin from the roots of Ferula latisecta.

OBJECTIVE
The genus of Ferula belongs to the tribe Peucedaneae, subfamily of Apioideae and family of Umbelliferae with 133 species distributed throughout the Mediterranean area and central Asia, especially in the former USSR and neighboring countries such as Iran. The popular Persian name of the most of these species is "Koma". In this research we tried to isolate and elucidate the structure of new sesquiterpene in the root of Ferula latisecta (F. latisecta).


MATERIALS AND METHODS
Dried and powdered roots of F. latisecta were extracted with CH2Cl2 using a Soxhlet apparatus. The extract was concentrated in vacuo to give a red extract. The extract was subjected to column chromatography on silica gel. (1)H NMR, (13)C NMR, DEPT, (1)H-(1)H COSY, HMBC, HSQC, and NOESY spectra were the methods we used to elucidate the structure of new sesquiterpene in this plant.


RESULTS
One new sesquieterpene coumarin, namely Latisectin and IUPAC name [1-(2-Hydroxy-4-methoxy-phenyl)-3,4,8,12-tetramethyl-trideca-4,7,11-trien-1-one ] , together with one known compound , Kopetdaghin C, were isolated from the root of F. latisecta.


CONCLUSION
In this research the structure of one new and one known sesquiterpene in the root of F. latisecta was elucidated.


Introduction
The genus of Ferula belongs to the tribe Peucedaneae, subfamily of Apioideae and family of Umbelliferae with 133 species distributed throughout the Mediterranean area and central Asia, especially in the former USSR and neighboring countries such as Iran (Evans, 1989;Mozaffarian, 1983;Heywood, 1985). More than 70 species of Ferula have already been investigated phytochemically (Diab et al., 2001;Iranshahi et al., 2004a;Abd El-Razek et al., 2003). Several species of this genus have been used in folk medicine (Chen et al., 2000). The Iranian flora comprises 30 species of Ferula of which 15 are endemic. (Mozaffarian, 1983(Mozaffarian, , 1996. The popular Persian name for the most of these species is "Koma" (Mozaffarian, 1996).
F. latisecta Rech. f. & Aellen. Is a plant endemic to Iran (Hedge et al., 1982) and no phytochemical studies of this species have been reported to date. One report showed an inhibitory effect of F. latisecta root extract on gram positive bacteria and candida albicans (Iranshahi et al., 2008). One of traditional usage of this plant is related to its anti-parasitic effects. Also because of sulfide compounds in this plant, it has been used to treat gastro-intestinal disorders in domestic animals. The aim of this study is isolation and elucidation the compounds in the root of this plant.

Plant material
The roots of F. latisecta were collected from the Hezarmasjed Mountains, Khorasan Razavi province, Iran, in April 2011. The plant material was identified by Mohammad Reza Joharchi, Ferdowsi University of Mashhad Herbarium (FUMH). A voucher specimen (No. 1004) has been deposited at the herbarium of School of Pharmacy, Mashhad University of Medical Sciences.

Extraction and isolation
Dried and powdered roots of F. latisecta (500 g) were extracted with CH 2 Cl 2 using a Soxhlet apparatus. The extract was concentrated in vacuo to give a red extract (18 g) and then they subjected to column chromatography on silica gel (5×50 cm) The fractions were compared by TLC, and those giving similar spots were combined and thirteen fractions were finally obtained. Fractions required more purification with PTLC (silica gel using petrol: EtOAc, in different ratio, 20×20 cm, glass plates , each plate was run two times). After further purification, each purified fraction was kept in glass vial without any solvent and reserved in freezer in-18 º C, but some of them were unstable and finally only 2 fractions were obtained for structure identification.

Result
Normal-phase column chromatography of the dichloromethane extract of roots, followed by preparative TLC, afforded two natural products (Figure 1).  Its structure was established with 1 H and 13 C NMR spectra (Table 1). Compound 2, Kopetdaghin C, has been known before in Dorema kopetdaghin (Iranshahi et al., 2007b), and final structure of Kopetdaghin C is described in details in Table 2.